Internet Explorer
Internet Explorer or IE is Microsoft's web browser. It comes integrated into windows and doubles as a file system browser as well as help viewer this integration combined with the ActiveX component of IE has made it incredibly easy to use. A mundane bug in the browser as a gateway for a system-level exploit in most versions of windows that have been released in a successful attempt to steal market share from each other. Microsoft and Netscape added many browser-specific capabilities into their respective browsers many of these features are still widely used today although much effort has been made to convince browser makers that interoperability is the key to the web web's success. Given IE's massive market share Microsoft has been particularly stubborn in adopting this mentality which is logical from a business perspective. This introduces difficulties to a web designer that are viewed as unnecessary, unavoidable and a result of laziness or apathy on the part of Microsoft. Other designers consider Internet Explorer to be the only relevant browser but this paradigm is an artifact of outdated thinking and browser surveys have reported almost uninterrupted loss of IE market share. Since June 2004 Internet Explorer 7 was release in October of 2006 catching its feature set up to browsers such as Firefox, Safari and Opera who have had some of ie7 ie7's 'new' features for 4-10 years
External Links:
Unofficial yet comprehensive browser usage stats at wikipedia category web browsers